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Rather, blue eyes result from structural color in combination with certain concentrations of non-blue pigments. The iris pigment epithelium is brownish black due to the presence of melanin. [54] Unlike brown eyes, blue eyes have low concentrations of melanin in the stroma of the iris, which lies in front of the dark epithelium.
Cyanopsia is rare and occurs primarily in individuals who have undergone cataract surgery or used specific medications. It is not influenced by ethnic, or geographic factors but is more common in certain demographic groups. Older adults are more likely to experience cyanopsia due to the higher frequency of cataract surgery in this age group.
Melanin in the eyes, in the iris and choroid, helps protect from ultraviolet and high-frequency visible light; people with blue, green, and grey eyes are more at risk of sun-related eye problems. Furthermore, the ocular lens yellows with age, providing added protection.
Blue, brown, hazel, green and all of the shades in between—there is one in the list that a small two percent of the population hold. Can you guess what the rarest eye color in the world is?
Hazel eyes tend to change colors due to Rayleigh scattering—the same factor that makes the sky appear blue. This optical effect occurs in the stroma, which is a thin layer of tissue in front of ...
Waardenburg syndrome is a group of rare genetic conditions characterised by at least some degree of congenital hearing loss and pigmentation deficiencies, which can include bright blue eyes (or one blue eye and one brown eye), a white forelock or patches of light skin.
Eye cancers can be primary (starts within the eye) or metastatic cancer (spread to the eye from another organ). The two most common cancers that spread to the eye from another organ are breast cancer and lung cancer. [2] Other less common sites of origin include the prostate, kidney, thyroid, skin, colon and blood or bone marrow.
Uveal melanoma is a type of eye cancer in the uvea of the eye. [4] It is traditionally classed as originating in the iris, choroid, and ciliary body, but can also be divided into class I (low metastatic risk) and class II (high metastatic risk). [4]